This invention relates to a remote controlled auxiliary lock effective in particular against theft such as by picking.
In recent years, damage due to picking is increasing. Picking is an act in which a special tool is inserted into a keyhole to open the lock in an extremely short period of time for theft, and the damage is large because the entrance door is opened and things in rooms can be completely stolen.
In order to prevent damage due to picking, one conceivable method is to replace the lock with a dimple type or magnetic type one which is more difficult to pick.
But for this method, a special tool or a specialist is needed for replacement. Also, some type of locks cannot be replaced.
As a simple method, it is conceivable to mount a plurality of auxiliary locks so that it takes a longer time to open the locks, thereby making thieves hesitate to enter.
But even if a plurality of auxiliary locks are provided, since they have keyholes, it is not impossible to open them by use of a tool. Further, if a plurality of auxiliary locks are provided, it is time-consuming to open and close such locks in daily lives.
Thus, a remote control type auxiliary lock is conceivable. For example, if a lock can be opened and closed by a remote controller, since the lock has no keyhole, it is impossible to open it even if a tool is used. Further, the lock can be opened and closed quickly.
But for a remote control type lock, a power source is necessary to drive the auxiliary lock. It is conceivable to use an AC power source for such a power source. But wiring is necessary and there may be no outlet in the hall. Thus, it is preferably battery-driven.
But in the case of battery driving, there is a problem that if the battery dies with the lock fastened, it is impossible to open it.
Also, if the batteries die in a short period of time, they have to be replaced frequently. Replacing them will be time-consuming and maintenance cost will be high. This markedly reduces the merit of the remote control type.
An object of this invention is to prevent the door from being kept shut even if the battery dies and to make it possible to use for a long time with a battery.
According to this invention, there is provided a remote controlled auxiliary lock comprising an auxiliary lock body mounted to a door and a wireless remote controller, the lock body comprising a bolt protrudable from a lock surface, an actuator for actuating the bolt, a lock seat engageable with the bolt, and a built-in battery for activating the actuator, the auxiliary lock body comprising a wireless receiver means, a drive means for activating the actuator when the wireless receiver means receives an open-close signal from the wireless remote controller, a first voltage detecting means and a second voltage detecting means for detecting that the voltage of the battery has lowered to respective predetermined voltages, and an alarm means, the wireless remote controller comprising a wireless transmission means and an open-close signal generating means for sending the open-close signal to the wireless transmission means, wherein when the first voltage detecting means detects that the voltage of the battery has dropped to a predetermined first voltage, an alarm is generated by the alarm means, and when the second voltage detecting means detects that the voltage of the battery has dropped further to a predetermined second voltage, the actuator is activated to push down the bolt inside the lock surface.
With this arrangement, when the first voltage detecting means detects that the voltage of the battery has dropped to a predetermined level at which replacement is necessary, an alarm is generated by the alarm means, which uses sound or light to urge replacement of the battery.
If the battery is not replaced even after the alarm is generated, when the second voltage detecting means detects a predetermined second voltage, e.g. a minimum voltage at which the actuator can be activated, the actuator is activated to withdraw the bolt inside the lock surface. Thus, it is possible to prevent the door from being kept closed even if the battery dies. At this time, while the auxiliary lock becomes ineffective, the door is locked by its main lock.
By providing the auxiliary lock body with an electric power supply means for intermittently supplying electric power from the built-in battery to the wireless receiver means to activate it, it is possible to prevent trouble in receiving signals while retarding exhaustion of the battery, so that it is possible to use the lock for a long time without replacing the battery.
Further, by driving the actuator by means of a motor through a clutch mechanism, it is possible to push down the bolt by releasing the coupling of the actuator and the motor with the clutch mechanism, so that the lock can be opened from inside the door without using remote control.
Also, by providing the auxiliary lock body with an ID distinguishing means and providing the wireless remote controller with an ID signal generating means, the auxiliary lock can be operated only by a specific remote controller. Thus, for example, it is possible to make it difficult to manufacture a remote controller for a duplicate key by complicating the code signal used for the ID signal. Further, for example, if it is designed such that the body will not be activated unless it continuously receives identical ID signals twice (or N times) at a constant speed, it is possible to easily strengthen security.
Other features and objects of the present invention will become apparent from the following description made with reference to the accompanying drawings, in which: